Synthesis and insecticidal activity of new 3-benzylfuran-2-yl N,N,N',N'-tetraethyldiamidophosphate derivatives

BACKGROUND: A series of 3-benzylfuran-2-yl N,N,N',N'-tetraethyldiamidophosphate derivatives were synthesized as potential new agents to control insects. Their structures were confirmed on the basis of IR, NMR and MS analyses. RESULTS: Ten 3-benzylfuran-2-ylN,N,N',N'-tetraethyl derivatives were prepared from the compound furan-2-yl N' (N,N,N',N'-tetraethyldiamidophosphate). The contact toxicity of all derivatives, at a dose of 10 microg mg(-1) insect, was evaluated against four insect species, Ascia monuste orseis Latr. (Lepidoptera: Pyralidae), Diaphania hyalinata (L.) (Lepidoptera: Pyralidae), Sitophilus zeamais Mots. (Coleoptera: Bruchidae) and Solenopsis saevissima (Smith) (Hymenoptera: Formicidae). The mortality range observed for some derivatives, such as 3-(3-methylbenzyl)furan-2-yl N,N,N',N'-tetraethyldiamidophosphate (82.5% mortality against D. hyalinata; 100% mortality against S. saevissima), was comparable with that of the commercial insecticide chlorpyrifos-methyl. The biological activity of the derivatives depended on the substitution pattern of the benzylic ring. Furan-2-yl N,N,N',N'-tetraethyldiamidophosphate, furan-2-yl N,N-diethylamidochlorophosphate and difuran-2-yl N,N-diethylamidophosphate were also evaluated, displaying, in some cases, activity comparable with that of chlorpyrifos-methyl (90%, 100% and 97.5% respectively against A. monuste orseis). Considerable activity was observed for some furan-2(5H)-ones evaluated. CONCLUSION: Ten 3-benzylfuran-2-yl N,N,N',N'-tetraethyldiamidophosphate derivatives were synthesized and fully characterized from a chemical point of view. The results obtained from the biological assays indicate that this class of compounds can be utilized for the design of new substances endowed with insecticidal activity.     

Screening and characterization of sex-specific DNA fragments in the freshwater fish matrinchã, Brycon amazonicus (Teleostei: Characiformes: Characidae)

The matrinch? Brycon amazonicus, a commercially important freshwater fish resource, has no heteromorphic sex chromosomes so far described. In the present study, we performed a screening of sex-associated DNA markers in this species, through the use of a random amplified polymorphic DNA (RAPD) assay and a genomic DNA restriction digestion analysis. DNA digestions evidenced no differences between sexes. Sixty-six random primers were used in pooled and individual DNA samples of males and females, and the analysis of the RAPD fingerprints revealed one female sex-associated band. Cloning and sequencing of this band led to the identification of two distinct DNA segments. While one of the isolated fragments showed a significant identity with a described protein gene (phosphatidylinositol glycan anchor biosynthesis, class W), the other fragment, composed of 535?bp, corresponds to a novel DNA marker. Further experiments were performed with this second DNA fragment in order to verify its sex-specificity. Data on dot blot hybridization, using total DNA of both sexes, confirmed its female-specificity in B. amazonicus. A primer set was designed based on its sequence data and used in PCR with DNA samples of this species, leading to diagnose the animals' sexes with a 100?% overall accuracy through a sequence characterized amplified region approach. No amplification results were found for two other species of the genus-B. orbignyanus and B. lundii. The obtained data can lead to the hypothesis that B. amazonicus may present heteromorphic sex chromosomes that should be in an early phase of differentiation.     

Incorporating information on bottlenose dolphin distribution into marine protected area design

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Spirulina meal has acted as a strong feeding attractant for Litopenaeus vannamei at a very low dietary inclusion level

The present work aimed at studying the growth performance and feeding preference of Litopenaeus vannamei juveniles fed on diets supplemented or not with Spirulina meal. Litopenaeus vannamei juveniles (3.89 ± 0.25 g) were stocked for 72 days in 28 round 500‐L tanks at 44 shrimp/tank (77 juveniles/m²). The diets were supplemented with 0.5% of a commercial feed attractant (C25 and C50) or with Spirulina meal (S25 and S50). In C25/S25 and C50/S50 there were reductions of 25% and 50% in fishmeal inclusion level respectively. In a further study, two feeding trays with different diets were allowed to shrimp at the same moment and they were located in opposite walls of the tank. The feed remains in each feeding tray were collected and weighted to calculate the dry feed remains. The weekly growth rate of shrimp fed on S25 (0.89 ± 0.03 g) was not significantly different from those fed on C25 (0.89 ± 0.01 g). The attractiveness experiment showed that S25 was preferred significantly more by shrimp than C25. In conclusion, Spirulina meal added at 0.5% in a complete diet for L. vannamei juveniles, with 14% of Peruvian fishmeal, has proved itself as a nutritionally efficient feeding attractant.     

Kinetics of Lead Bioaccumulation from a Hydroponic Medium by Aquatic Macrophytes Pistia stratiotes

The goal of this work was to study quantitatively lead bioaccumulation from a lead-doped nutrient medium by using a living aquatic macrophytes Pistia stratiotes. Several sets of aquatic plants with approximately 30 g weight were grown in greenhouse conditions and in hydroponic solutions supplied with a non-toxic Pb²⁺ concentration. The synchrotron radiation total X-ray fluorescence spectrometry was used to determine the metal concentrations in dry plants and hydroponic media as a function of time. Four different non-structural bioaccumulation models were applied to describe the process dynamics and to estimate the accumulated lead maximum capacity and rate constants. According to the experimental data, both biosorption and bioaccumulation mechanisms can be considered. Due to the low desorption rate constant, the experimental data were well described by the irreversible kinetic model. The results concerning modeling of living macrophytes’ metal bioaccumulation kinetics can be used to predict the heavy metal removal dynamics from wastewaters in artificial wetlands.     

Reduction of Hexavalent Chromium in Soil and Ground Water Using Zero-Valent Iron Under Batch and Semi-Batch Conditions

Chemical remediation of soil and groundwater containing hexavalent chromium (Cr(VI)) was carried out under batch and semi-batch conditions using different iron species: (Fe(II) (sulphate solution); Fe⁰ _G (granulated elemental iron); ZVIne (non-stabilized zerovalent iron) and ZVIcol (colloidal zerovalent iron). ZVIcol was synthesized using different experimental conditions with carboxymethyl cellulose (CMC) and ultra-sound. Chemical analysis revealed that the contaminated soil (frank clay sandy texture) presented an average Cr(VI) concentration of 456?±?35 mg kg^?1. Remediation studies carried out under batch conditions indicated that 1.00 g of ZVIcol leads to a chemical reduction of ～280 mg of Cr(VI). Considering the fractions of Cr(VI) present in soil (labile, exchangeable and insoluble), it was noted that after treatment with ZVIcol (semi-batch conditions and pH 5) only 2.5% of these species were not reduced. A comparative study using iron species was carried out in order to evaluate the reduction potentialities exhibited by ZVIcol. Results obtained under batch and semi-batch conditions indicate that application of ZVIcol for the “in situ” remediation of soil and groundwater containing Cr(VI) constitutes a promising technology.     

Transformation of Sclerotinia sclerotiorum with the green fluorescent protein gene and fluorescence of hyphae in four inoculated hosts

To obtain a genetic marker to observe and study the interaction of Sclerotinia sclerotiorum with its hosts, isolates ND30 and ND21 were transformed using pCT74 and gGFP constructs, both containing genes for the green fluorescent protein (GFP) and hygromycin B phosphotransferase. Putative transformants were obtained using polyethylene glycol-mediated transformation of protoplasts. Seven stable gfp transformants were identified and evaluated for fluorescence in vitro and in planta , pathogenicity and colonization of host tissues. Real-time quantitative polymerase chain reaction detected a single copy of the gfp gene in transformants. Fluorescence was quantified directly from mycelium and protein extracted from hyphae. The seven transformants (four from ND30 and three from ND21) were pathogenic on dry bean, canola, soybean and sunflower. However, depending on the host, three transformants differed significantly ( P  = 0·05) in the length of lesions formed compared to the wild-type. Hyphae fluoresced in plant tissue and could clearly be distinguished from plant cells. Infection and colonization of tissues were clearly visible with a fluorescent microscope. Transformants differed in the intensity of GFP expression both in vitro and in planta .     

Suitability of different artificial diets for development and survival of stages of the predaceous ladybird beetle <Emphasis Type="Italic">Eriopis connexa</Emphasis>

The ladybug Eriopis connexa (Germar) (Coleoptera: Coccinellidae) is an important natural enemy of various pests. The potential of rearing it on 17 different diets was evaluated. The percentage of E. connexa adults was higher when its larvae received only eggs of Anagasta kuehniella (Zeller) (Lepidoptera: Pyralidae) after freezing for 1 day (92.5%) or combined in artificial diets with honey and water (82.5% to 100.0%). The viability from larvae to adult was 72.5% with eggs of A. kuehniella (after 1 day’s freezing) plus an artificial diet based on pet food. No adults of E. connexa were obtained with artificial diets as a stand-alone food source. The duration of the larval period to adult of this predator was longer, but with low viability, with only A. kuehniella eggs (after 6 months’ freezing) or with eggs + artificial diets. Eggs of A. kuehniella (after 1 day’s freezing) supplied separately or along with artificial diets were more appropriate to rear E. connexa and both diets can be used for mass rearing of this natural enemy.     

Toxicity of botanical insecticides on Diaphania hyalinata,their selectivity for the predatory ant Paratrechina sp., and their potential phytotoxicity on pumpkin

The use of botanical insecticides could be an alternative efficient pest management in Cucurbitaceae against melonworm Diaphania hyalinata and less harmful to its predator. Few studies jointly assess the efficiency of botanical insecticides, their effects on pest, and their effect on the natural enemy and target crop. Here we examine (1) their impact against the melonworm D. hyalinata, a key pest of Cucurbitaceae, (2) their toxicity to the predatory ant Paratrechina sp., and (3) their phytotoxicity to pumpkin plants. The botanical insecticides citronella oil and eucalyptus oil were highly toxic to D. hyalinata and they exhibited to be less harmful for the predatory ant Paratrechina sp. Andiroba oil, eucalyptus oil, garlic extract, and citronella oil caused feeding inhibition of the D. hyalinata larvae. Eucalyptus oil, andiroba oil, garlic extract, and rotenone inhibited the oviposition of D. hyalinata. None of the insecticides was phytotoxic to pumpkin plants. Eucalyptus oil and citronella oil have induced high mortality and altered the behavior of target pests. In addition, they were selective for the predator Paratrechina sp. and not exhibited phytotoxicity on pumpkin plants. Eucalyptus oil and citronella oil seem the most promising compounds for incorporation into melonworm management programs, because they induced high mortality and altered the behavior of target pests and were selective for the predator Paratrechina sp.     

Dietary methionine requirement of the pre‐adult gibel carp (Carassius auratus gibeilo) at a constant dietary cystine level

A 62‐day growth trial was conducted to determine the dietary Met requirement of the pre‐adult gibel carp (Carassius auratus gibeilo) (initial weight of 51.0 ± 0.02 g). Six isonitrogenous and isoenergetic diets using fish meal, blood meal and pea protein concentrate as protein sources supplemented with crystalline amino acids were formulated to contain graded levels of dietary Met (4.44, 6.56, 8.55, 10.90, 12.79 and 15.05 g kg^?1, respectively) at a constant dietary cystine level of 3.99 g kg^?1. The results showed that weight gain rate and protein productive value significantly increased with the dietary Met levels from 4.44 to 8.55 g kg^?1, then reached plateau at 10.90 g kg^?1. Plasma HDL‐C and TC were increased with dietary Met levels. Fish supplied with 4.44–8.55 g kg^?1 Met showed lower plasma AST level than that of other groups. Plasma TG, LDL‐C and ALT levels were stable for all treatments. The activity of intestinal γ‐GT was increased with dietary Met levels. The optimal requirement of Met for pre‐adult gibel carp (>50 g) was a range from 7.86 g kg^?1 to 9.84 g kg^?1 dry diet or 16.9 g kg^?1 to 23.0 g kg^?1 of dietary protein with the presence of 3.99 g kg^?1 Cys for the satisfied lipid metabolism and maximum growth, respectively.